This invention relates to a sanitary article such as a disposable diaper, a sanitary napkin or a body fluid absorbent pad for incontinence which includes a multi-layered absorbent member.
Japanese Patent Application Publication No. 1997-253259A describes a disposable diaper comprising a liquid-pervious topsheet, a liquid-impervious backsheet and upper and lower liquid-absorbent panels both disposed between the topsheet and the backsheet. The upper liquid-absorbent panel is formed with a plurality of openings extending through this panel in a direction of its thickness. This diaper is described as being capable of preventing any amount of excretion discharged thereon from staying on the topsheet by receiving the entire amount of excretion in the respective openings formed on the liquid-pervious topsheet and then transferring this into the upper and lower liquid-absorbent panels.
With the diaper disclosed in the publication, excretion discharged thereon merely spreads within the respective panels as widely as possible in the course being absorbed by these panels. In other words, the extent over which excretion is absorbed by the panels is disadvantageously limited to the position at which excretion has been discharged on the diaper. Depending on a capacity of the diaper, excretion discharge focussed or localized may cause a certain amount of excretion to stay on the topsheet or in a limited zone, particularly in some of the openings of the panels. In this case, the amount of excretion once received in the openings may flow back toward the topsheet as the panels are compressed under a wearer""s body weight.
An object of this invention is to provide a sanitary article having a multi-layered absorbent member designed so that excretion discharged thereon may rapidly spread as widely as possible to prevent any amount of excretion from staying on a topsheet or in the limited zone of the article and thereby to prevent excretion once absorbed in the article from flowing back toward the topsheet.
According to this invention, there is provided a sanitary napkin having multi-layered absorbent member comprising, a panel made of a fibrous web having a compressive recovery elasticity, a plurality of openings extending through the panel in a thickness direction thereof and spaced one from another in a direction orthogonal to the thickness direction and a plurality of fibrous assembly regions extending between each pair of adjacent the openings.
The article further comprises the panel including two or more individual panels stacked one on another in the thickness direction each having a plurality of openings out of alignment with the corresponding openings in the individual panel immediately underlying the precedent individual panel and each of the openings in the precedent individual panel being divided in two or more sections by the fibrous assembly regions.
The multi-layered absorbent member according to this invention makes it possible to deflect the flowing direction of excretion by the fibrous assembly ribs (fibrous assembly regions) while the flow of excretion is successively absorbed by the respective panels so that excretion may spread as widely as possible from the top panel toward the bottom panel. In this way, the entire volume of the absorbent member can be efficiently utilized. Even if excretion is discharged onto a limited spot of the absorbent member, it is not apprehended that a certain amount of excretion might stay in or on this spot of the absorbent member since the discharged amount of excretion can rapidly spread within the absorbent member and is uniformly absorbed therein.
The absorbent member in which the total opening area of the openings progressively increases from the top panel toward the bottom panel can effectively avoid undesirable back flow of excretion even when the absorbent member is compressed in the direction of its thickness. This is because the total opening area of the openings progressively decreases from the bottom panel toward the top panel and the density of the fibrous assembly ribs in the respective panels correspondingly increases in this direction.
The absorbent member in which the fiber density progressively decreases from the top panel toward the bottom panel is effective particularly for high viscosity excretion such as loose passage or menstrual discharge since the absorption capacity for such high viscosity excretion progressively increases from the top panel toward the bottom panel so that the flow of excretion may be rapidly moved downward in the absorbent member.
The absorbent member being able to utilize the entire volume thereof is suitable particularly as the important component of the sanitary article such as the liquid-absorbent pad for incontinence control.